School buses are the safest way for children to get to school. About 24 million children ride a school bus every day, and most students spend an hour and a half each weekday in a school bus.

Because almost all school buses run on diesel fuel, children are exposed to the pollution in diesel exhaust. Children can be exposed to diesel exhaust if they ride in a bus or if they play or wait in school bus loading zones where buses are idling with their engines running. Exhaust from buses that idle outside schools can also pollute the air inside the school.

Diesel exhaust contains many harmful air pollutants, including particulate matter, volatile organic compounds, and other chemicals that can cause cancer. Exposure to diesel exhaust can cause respiratory problems, asthma, allergies, and lung damage. Children are more affected by the harmful effects of air pollution because they breathe at a faster rate than adults, and their lungs are still developing.

Older school buses built before 1977 may not meet either current safety standards or environmental standards.

Children can reduce their exposure to diesel exhaust from school buses by sitting toward the front of the bus and keeping a bus window open if the weather allows. They can also avoid playing outside near a school bus loading zone if buses are there with their engines idling.

There are efforts to “clean up” the impact of school bus exhaust. Some school systems have developed anti-idling policies requiring buses to shut off their engines when idling, and some school buses are being retrofitted with cleaner engines.

This description is based on the information found in the Web links listed with this topic.